Unique

The Unique annotation is used to indicate if an entity class's field is unique to the table when being persisted to the database. More concisely, this annotation is used to define a unique constraint on a column. This has no effect on a field that is marked transient.

Unique Example

The following example shows how the field mBar is made unique.

public class Foo {

    @Unique
    private int mBar;

    public int getBar() {
        return mBar;
    }

    public void setBar(int bar) {
        mBar = bar;
    }

}